Rafael Nadal’s uncle, Toni Nadal, is one of the people who believe that the former World No. 1 will return to top form for the next ATP season. The long-time trainer of Nadal stated with confidence that he sees his ward challenging and winning more Grand Slam titles at this point of his career.

"Yes. I couldn't do this work if I thought that he couldn't win more Grand Slams. No, no, no, I think that he can win more Grand Slams,” the elder Nadal told ESPN. “He can win the Australian Open in January. And he can win Wimbledon, too."

Rafael Nadal, who has won 14 Grand Slam titles in his career, is considered one of the best players in the game, but he has struggled in the past two seasons. Rafa has dropped all the way down to World No. 10 in the middle of the 2015 season but has recovered in the latter part, climbing back to World No. 5 in the year-end rankings.

Nadal’s last Grand Slam win was in 2014 at the French Open, and he has since failed to get past the quarterfinals of any major tournament's championship. Nadal’s record of 14 Grand Slam titles is tied with Pete Sampras for the second all-time total for any men’s singles player. It is three short of Federer’s record of 17 major titles.

The dominance of current World No. 1 Novak Djokovic, the resurgence of rival Roger Federer and the rise of other top contenders like Kei Nishikori and Stan Wawrinka, among others, have made it difficult for Nadal to win another Grand Slam title.

Toni Nadal admitted in the same interview that Rafa's struggles in recent years has been more about the mental aspect of the game. Nadal’s uncle believes Rafa has now recovered mentally.

"First of all, and this is the most important thing, is the tranquility. Rafael is much more comfortable on the court now,” Toni added.

Nadal performed well at the season-ending tournament at the ATP World Tour Finals where he made the semifinals. The first Grand Slam of the 2016 season, the Australian Open, is scheduled from Jan. 18 to Jan. 31, and Nadal is considered one of the top contenders to challenge defending champion Djokovic for the title.